There are more client computers on the internet.
In general, every computer on the internet is either a client, a server, or both. For instance, a web server is a computer that provides web pages to clients. A single web server can handle up to thousands of clients. Additionally, that web server may itself be a client to another computer that's a database server. This asymmetry in the number of clients and servers out there is one of the major reasons that most customer level ISPs (Internet Service Providers) provide asymmetric data connections to the internet for their customers. A short request of a few hundred bytes sent by a customer may results in a response from the remote server of several million bytes.
